When an insurgent's homemade bomb injured two ABC News reporters Sunday, it brought to prime time a truth of this unusual conflict: One of the most dangerous places for US troops in Iraq is in their own trucks.
Thirty months into the Iraq war, improvised explosive devices, or IEDs, account for more than half of all American injuries or deaths in combat. The weapon is so primitive that military bomb-squad schools once saw them as little more than the work of kids and miscreants. Now, troops bolt extra armor to their Humvees, and new arrivals receive IED awareness training.
Last week, the Pentagon even announced that its IED task force would become permanent, one of several recent moves that suggests the issue is becoming a greater priority.
Sunday's attack is just one among many each day that underscore the difficulty the Pentagon faces. For every advance in training and technology, insurgents can build a bomb with a car battery and a washing-machine timer. It is the simplicity and adaptability of IEDs that defy easy solutions and suggest that defeating IEDs depends as much on breaking the broader insurgency as any new tool or technique.
"There are all kinds of ways to address it, but it's hard to eliminate," says Winslow Wheeler of the Center for Defense Information, a private research group in Washington. "The problem is fundamental to the nature of the insurgency."
For an enemy that blends into the background of Iraqi life and often strikes without ever being seen, the IED is the ideal weapon, made out of spare parts and stolen munitions, and easily hidden in a pothole or a pile of rags. Pentagon leaders call it the insurgents' weapon of choice, and the rate of attacks has steadily increased as the war has progressed, officials say.
Yet the casualties per attack have decreased, they note - a sign that countermeasures are beginning to work. "Between the increase in armor and the changes in tactics, the numbers of IED attacks that have been effective has gone down," said Gen. Peter Pace, chairman of the Joint Chiefs of Staff, in a November briefing.
The two injured in Sunday's blast - anchor Bob Woodruff and cameraman Doug Vogt - were embedded with an American unit. But they had decided to ride in a more lightly armored Iraqi vehicle before the explosion occurred. They have since been taken to a US military hospital in Germany, where they were in serious but stable condition at press time.
Particularly in recent months, the Pentagon has placed an increasing emphasis on countering IEDs. In December, the leadership of a temporary two-year-old IED task force passed from a one-star general to a four-star general, giving it far more clout at the Pentagon budget trough. Then last week, officials announced that the task force would become permanent.
Already, soldiers are already using new techniques and equipment - some of them as primitive and adaptive as IEDs. One unit hung chains from a six-foot boom in front of the truck, hoping they would trigger an IED before the vehicle drove over it. Other soldiers are using radio-frequency jammers to prevent insurgents from detonating IEDs by remote controls or garage-door openers.
For its part, the Office of Naval Research hopes to go further. It has begun what it calls a mini-"Manhattan Project," bringing together scientists from academia, industry, and the military to find longer-term solutions to the IED threat.
One scientist involved with the program suggests that social science could play a crucial role in understanding - and breaking - the chain that leads to an IED attack. "It takes a team to do this, and not everyone in that team is politically motivated," says John Anderson of Case Western Reserve University in Cleveland. "The human dynamics are not well known."
And the human dynamics are what have made IEDs such a difficult problem. There is no "silver bullet," all agree. The best solution is better intelligence. But technical solutions, together with better practices, can cut into the toll, many say.
The military is already becoming more sophisticated in countering IEDs - in some cases, even thinking like the insurgents do. The insurgents clearly share information about IED techniques and locations that work best against coalition forces. So the Army is now developing a network of secure websites to allow captains and commanders to share best practices among themselves.
"If I'm Captain Wallace sitting out there and I want to know something about shaped charges, I can go to this knowledge network and pull down all the latest ... information," said William "Scott" Wallace, commander of the Army's Training and Doctrine Command, at a December briefing.
Such steps are encouraging, experts say, but they are careful to put the current effort in context. The Office of Naval Research's mini-Manhattan Project has but a fraction of what its 1940s namesake had, and the four-star general in charge of the Pentagon's anti-IED efforts is still far down on the Pentagon's fiscal food chain.
"As much attention as this is getting from the military, it still gets second billing at the Pentagon," says Noah Shachtman of DefenseTech.org. Its budget is "nothing compared to the big-ticket weapons systems." [Editor's note: The original version misidentified the address of Mr. Shachtman's website.]